Hy, everyone!
I have an error in ruby code of my plugin for Redmine. Error occurs then method Setting.plugin_myplugin['myplugin_setting']
is called.
Here traceback of this error:
NoMethodError (undefined method `plugin_myplugin' for #<Class:0x00000004874098>):
activerecord (3.2.17) lib/active_record/dynamic_matchers.rb:55:in `method_missing'
plugins/myplugin/lib/myplugin/patches/account_controller_patch.rb:36:in `login_with_myplugin'
actionpack (3.2.17) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (3.2.17) lib/abstract_controller/base.rb:167:in `process_action'
actionpack (3.2.17) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (3.2.17) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (3.2.17) lib/active_support/callbacks.rb:447:in `_run__4412462782733274046__process_action__1678150651014813342__callbacks'
activesupport (3.2.17) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.17) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
activesupport (3.2.17) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.17) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.2.17) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (3.2.17) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.2.17) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.17) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.17) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.17) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.2.17) lib/action_controller/metal/params_wrapper.rb:207:in `process_action'
activerecord (3.2.17) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (3.2.17) lib/abstract_controller/base.rb:121:in `process'
actionpack (3.2.17) lib/abstract_controller/rendering.rb:45:in `process'
actionpack (3.2.17) lib/action_controller/metal.rb:203:in `dispatch'
actionpack (3.2.17) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.2.17) lib/action_controller/metal.rb:246:in `block in action'
actionpack (3.2.17) lib/action_dispatch/routing/route_set.rb:73:in `call'
actionpack (3.2.17) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
actionpack (3.2.17) lib/action_dispatch/routing/route_set.rb:36:in `call'
journey (1.0.4) lib/journey/router.rb:68:in `block in call'
journey (1.0.4) lib/journey/router.rb:56:in `each'
journey (1.0.4) lib/journey/router.rb:56:in `call'
System specifications:
Redmine 2.5.1
apache2.2.22-1ubuntu1.5
Passenger 4.0.4
ruby 1.9.3p545
Does anyone know what could be the problem?
It is necessary to debug code.
Here Redmine loads plugin settings to class variable.
Here Redmine defines setter/geter for each setting.
And exactly your method plugin_myplugin does not appear in ##available_settings. So I think you should
check your init.rb file and check what plugin name you use.
check if any settings you define there (working example)
(if previous didn't help) debug core: check why your plugin settings don't appear in ##avaulable_settings (I think you should debug here)
This problem happened also to me.
With #gotva's answer suggestions I've been able to go deeper and I understood which was the cause for me. In my case, I've got 2 plugins:
one plugin has got its settings (registered in the standard way, i.e. calling the method settings inside Redmine::Plugin.register), and I was failing to reach its configuration page seeing the error reported in the question;
in the other plugin I was setting a given Setting (sorry for the pun) just after having registered the plugin (i.e. after the call to register).
The plugin with settings was working if I was keeping only it.
Since the Setting class loads settings when it's used for the first time, I'm pretty sure that the problem was that the plugin in which I was using Setting was getting loaded before the other: so when I declared the settings, Setting didn't load them anymore because it was been already called, leaving out the settings that I wanted to load.
Related
I have this line in my code:
student.user.try(:services).try( :where, {course_id: params[:current_course]} ).try(:first)
It gives the following error:
undefined method `where' for #<Array:0x007fc35070da30>
But when I use it without try like this:
student.user.try(:services).where("course_id = ?", params[:current_course] ).try(:first)
everything is OK.
What's the problem with try?
Per your request adding the backtrace:
activesupport (3.2.8) lib/active_support/core_ext/object/try.rb:36:in `try'
activerecord (3.2.8) lib/active_record/associations/collection_proxy.rb:89:in `method_missing'
app/controllers/trainings_controller.rb:926:in `block in transfer_students'
app/controllers/trainings_controller.rb:922:in `each'
app/controllers/trainings_controller.rb:922:in `transfer_students'
actionpack (3.2.8) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (3.2.8) lib/abstract_controller/base.rb:167:in `process_action'
actionpack (3.2.8) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (3.2.8) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (3.2.8) lib/active_support/callbacks.rb:491:in `_run__1196091745092505907__process_action__2696008159292751787__callbacks'
activesupport (3.2.8) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.8) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
activesupport (3.2.8) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.8) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.2.8) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (3.2.8) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.2.8) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.8) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.8) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.8) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.2.8) lib/action_controller/metal/params_wrapper.rb:207:in `process_action'
activerecord (3.2.8) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (3.2.8) lib/abstract_controller/base.rb:121:in `process'
actionpack (3.2.8) lib/abstract_controller/rendering.rb:45:in `process'
actionpack (3.2.8) lib/action_controller/metal.rb:203:in `dispatch'
actionpack (3.2.8) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
Moving this to an answer since it seemed to be helpful.
Reading the release notes, this seems to be the legacy behavior of Object.try. It was changed to the current expectation in Rails 4:
"Object#try will now return nil instead of raise a NoMethodError if the receiving object does not implement the method"
Rails 4.0 Release notes
Started getting loads of these errors today:
F, [2018-08-03T18:02:08.783602 #22987] FATAL -- :
ActionController::InvalidCrossOriginRequest (Security warning: an embedded <script> tag on another site requested protected JavaScript. If you know what you're doing, go ahead and disable forgery protection on this action to permit cross-
origin JavaScript embedding.):
actionpack (4.2.5) lib/action_controller/metal/request_forgery_protection.rb:225:in `verify_same_origin_request'
activesupport (4.2.5) lib/active_support/callbacks.rb:432:in `block in make_lambda'
activesupport (4.2.5) lib/active_support/callbacks.rb:239:in `block in halting'
activesupport (4.2.5) lib/active_support/callbacks.rb:506:in `block in call'
activesupport (4.2.5) lib/active_support/callbacks.rb:506:in `each'
activesupport (4.2.5) lib/active_support/callbacks.rb:506:in `call'
activesupport (4.2.5) lib/active_support/callbacks.rb:92:in `__run_callbacks__'
activesupport (4.2.5) lib/active_support/callbacks.rb:778:in `_run_process_action_callbacks'
activesupport (4.2.5) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.5) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.2.5) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.2.5) lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
activesupport (4.2.5) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (4.2.5) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.2.5) lib/active_support/notifications.rb:164:in `instrument'
....
I never saw this before. The only thing that changed in my application today: I set up a controller behind a generic route to catch routing errors that kept popping up in the prod log due to tons of lame script kiddies probing my sites, it was so annoying that I now just block every IP behind a routing error no questions asked.
I wouldn't care much about this but sometimes some very specific morons try to scrape my sites stealing my stuff so I'm mainly concerned about them coming up with something new, which would also mean I've slightly underestimated the size of their brains.
And now I am getting this error but I have no idea who tries to load what, where from, nothing relevant in the web server logs; how can I figure out what's going on?
i'm building my RoR app admin interface using active admin, got an exception i'm stuck on trying to set up custom actions :
ActiveAdmin.register Deal do
[:cancel, :release].each do |event|
member_action event , method: :patch do |deal|
deal.send :"#{event}!"
redirect_to admin_deal_path(deal), notice: "Your event was #{deal.current_state}"
end
action_item event, only: :show do
link_to event, url_for(action: event), method: :patch
end
end
end
The event links display well on the page but when clicking on one of them got the following exception :
ArgumentError (wrong number of arguments (0 for 1)):
app/admin/deal.rb:45:in `block (3 levels) in <top (required)>'
app/admin/deal.rb:45:in `block (3 levels) in <top (required)>'
actionpack (4.2.6) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.2.6) lib/abstract_controller/base.rb:198:in `process_action'
actionpack (4.2.6) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.2.6) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
activesupport (4.2.6) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.6) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.6) lib/active_support/callbacks.rb:555:in `block (2 levels) in compile'
activesupport (4.2.6) lib/active_support/callbacks.rb:505:in `call'
activesupport (4.2.6) lib/active_support/callbacks.rb:505:in `call'
activesupport (4.2.6) lib/active_support/callbacks.rb:92:in `__run_callbacks__'
activesupport (4.2.6) lib/active_support/callbacks.rb:778:in `_run_process_action_callbacks'
activesupport (4.2.6) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.6) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.2.6) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.2.6) lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
activesupport (4.2.6) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (4.2.6) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.2.6) lib/active_support/notifications.rb:164:in `instrument'
actionpack (4.2.6) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.2.6) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
activerecord (4.2.6) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.2.6) lib/abstract_controller/base.rb:137:in `process'
actionview (4.2.6) lib/action_view/rendering.rb:30:in `process'
Line 46 of admin/deal.rb is the line where member_action is called, it seems the activeadmin method is overided somehow somewhere or there is something else obvious i don't see...
Any idea where it could come from ? amon other gems I'm using cancancan, devise, and responders.
Thanks in advance
**UPDATED : full stacktrace **
My mistake was to pass a variable to the member_action block, the instance seems to be available via the resource helper
member_action :cancel, method: :patch do
resource.cancel!
redirect_to admin_deal_path(resource)
end
So I am trying to follow the tutorial here: http://guides.rubyonrails.org/getting_started.html
And I have some idea as to what's happening, but at this point I am becoming exponentially more upset and unequipped to look at this in a way that makes sense.here is my controller currently. it's very simple and I thought I knew what was going on:
articles_controller.rb
class ArticlesController < ApplicationController
def new
end
def create
#article = Article.new(article_params)
#article.save
redirect_to #article
end
private
def article_params
params.require(:article).permit(:title, :text)
end
end
routes.rb
Rails.application.routes.draw do
get 'welcome/index'
Rails.application.routes.draw do
resource :articles
root 'welcome#index'
end
end
But I am now out of my depth and can no longer proceed. If it makes a difference I am running windows 8 pro. Any help would be appreciated. I can tell the error has something to do with 'redirect_to' but I don't know anything outside of that!
My error now looks like:
NoMethodError in ArticlesController#create
undefined method `article_url' for #<ArticlesController:0x979bfc0>
Extracted source (around line #0):
app/controllers/articles_controller.rb:9:in `create'
And the stack trace looks like this:
actionpack (4.2.0) lib/action_dispatch/routing/polymorphic_routes.rb:268:in `handle_model_call'
actionpack (4.2.0) lib/action_dispatch/routing/url_for.rb:167:in `url_for'
actionpack (4.2.0) lib/action_controller/metal/redirecting.rb:95:in `_compute_redirect_to_location'
turbolinks (2.5.3) lib/turbolinks/xhr_headers.rb:21:in `_compute_redirect_to_location'
actionpack (4.2.0) lib/action_controller/metal/redirecting.rb:75:in `redirect_to'
actionpack (4.2.0) lib/action_controller/metal/flash.rb:57:in `redirect_to'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:61:in `block in redirect_to'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (4.2.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `instrument'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:60:in `redirect_to'
app/controllers/articles_controller.rb:9:in `create'
actionpack (4.2.0) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.2.0) lib/abstract_controller/base.rb:198:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.2.0) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
activesupport (4.2.0) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:117:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:234:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:169:in `block in halting'
activesupport (4.2.0) lib/active_support/callbacks.rb:92:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:92:in `_run_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_process_action_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.0) lib/abstract_controller/callbacks.rb:19:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `block in instrument'
activesupport (4.2.0) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.2.0) lib/active_support/notifications.rb:164:in `instrument'
actionpack (4.2.0) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.2.0) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
activerecord (4.2.0) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.2.0) lib/abstract_controller/base.rb:137:in `process'
actionview (4.2.0) lib/action_view/rendering.rb:30:in `process'
actionpack (4.2.0) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.2.0) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.2.0) lib/action_controller/metal.rb:236:in `block in action'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:73:in `call'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:42:in `serve'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:43:in `block in serve'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `each'
actionpack (4.2.0) lib/action_dispatch/journey/router.rb:30:in `serve'
actionpack (4.2.0) lib/action_dispatch/routing/route_set.rb:802:in `call'
rack (1.6.0) lib/rack/etag.rb:24:in `call'
rack (1.6.0) lib/rack/conditionalget.rb:38:in `call'
rack (1.6.0) lib/rack/head.rb:13:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/flash.rb:260:in `call'
rack (1.6.0) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.6.0) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/cookies.rb:560:in `call'
activerecord (4.2.0) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.2.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:647:in `call'
activerecord (4.2.0) lib/active_record/migration.rb:378:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.2.0) lib/active_support/callbacks.rb:88:in `call'
activesupport (4.2.0) lib/active_support/callbacks.rb:88:in `_run_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:734:in `_run_call_callbacks'
activesupport (4.2.0) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (4.2.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/reloader.rb:73:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
web-console (2.0.0) lib/action_dispatch/debug_exceptions.rb:18:in `middleware_call'
web-console (2.0.0) lib/action_dispatch/debug_exceptions.rb:13:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.2.0) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.2.0) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `block in tagged'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:26:in `tagged'
activesupport (4.2.0) lib/active_support/tagged_logging.rb:68:in `tagged'
railties (4.2.0) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.6.0) lib/rack/methodoverride.rb:22:in `call'
rack (1.6.0) lib/rack/runtime.rb:18:in `call'
activesupport (4.2.0) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
rack (1.6.0) lib/rack/lock.rb:17:in `call'
actionpack (4.2.0) lib/action_dispatch/middleware/static.rb:113:in `call'
Basically the "undefined method `article_url' for " means that rails can't find an appropriate route for the #article record. When defining a route, rails generates two methods ending in _url and _path. You can use them in your application to access the respective urls without hardcoding them. Looking at the code in your routes.rb file, I have found three things:
You only need one call to Rails.application.routes.draw
The key word for generating the CRUD routes for a model is "resources" (plural), not "resource" (singular)
(Not concerning the error) Your "get 'welcome/index'" looks not finished. Maybe you meant something line "get '/index', to: 'welcome#index'". The first string specifies the url path, the to specifies the controller#action.
Try with the following routes.rb:
Rails.application.routes.draw do
resources :articles
root 'welcome#index'
end
I recommend that you also go through the routing guide while you are at it. Good luck!
Ah you see, the problem is that you used the singular resource word, not the resources (note the s), in your case you should be using resources, because you have multiple articles
More about resources, and resource
You are redirecting to the #article show page after creating article but you don't have this method defined in your ArticlesController. You have to define that method and create a view for it. Also, what are your routes?
This is one hard code that implement resource work
You can pass json object to redirect_to
class ArticlesController < ApplicationController
def show
#article = Article.find(params[:id])
end
def new
end
def create
#article = Article.new(article_params)
#article.save
redirect_to articles_path({:id => #article.id})
end
private
def article_params
params.require(:article).permit(:title, :text)
end
end
I’m implementing paper trail like feature in my rails app. In order to do this, I’m serializing object in YAML. I’ve got item_at_version method, which basically does YAML::load(cached_object) – this works pretty well, however, I have no idea why, sometimes it returns undefined class/module _class name_.
It works with models like Event, Conversation, Note, and many more, but without any reason, it seems to throw that error for models like Dataset, Comment, Student (I’ve tried to find any pattern for that, without any luck).
I’m using rails 3.2.8, ruby 1.9.3p327, psych as YAML Engine (Psych::Version returns 1.3.4).
Ps. When I add require 'model_name' on top of that file, it works like a charm.
Any ideas what should I change/add to get this working?
Edit:
There’s no much code which I can share:
def item_at_version
YAML::load(cached_object)
end
But maybe backtrace would be interesting:
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:312:in `path2class'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:312:in `resolve_class'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:219:in `visit_Psych_Nodes_Mapping'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:20:in `accept'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:238:in `visit_Psych_Nodes_Document'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/visitor.rb:15:in `visit'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/visitor.rb:5:in `accept'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:20:in `accept'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/nodes/node.rb:35:in `to_ruby'
~/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych.rb:128:in `load'
app/models/history_version.rb:7:in `item_at_version'
app/controllers/history_controller.rb:8:in `show'
actionpack (3.2.8) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (3.2.8) lib/abstract_controller/base.rb:167:in `process_action'
actionpack (3.2.8) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (3.2.8) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (3.2.8) lib/active_support/callbacks.rb:502:in `_run__1697733322876708236__process_action__1122943786273335015__callbacks'
activesupport (3.2.8) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.8) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
activesupport (3.2.8) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.8) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.2.8) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (3.2.8) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.2.8) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.8) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.8) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.8) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.2.8) lib/action_controller/metal/params_wrapper.rb:207:in `process_action'
activerecord (3.2.8) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (3.2.8) lib/abstract_controller/base.rb:121:in `process'
actionpack (3.2.8) lib/abstract_controller/rendering.rb:45:in `process'
actionpack (3.2.8) lib/action_controller/metal.rb:203:in `dispatch'
actionpack (3.2.8) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.2.8) lib/action_controller/metal.rb:246:in `block in action'
actionpack (3.2.8) lib/action_dispatch/routing/route_set.rb:73:in `call'
actionpack (3.2.8) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
actionpack (3.2.8) lib/action_dispatch/routing/route_set.rb:36:in `call'
journey (1.0.4) lib/journey/router.rb:68:in `block in call'
journey (1.0.4) lib/journey/router.rb:56:in `each'
journey (1.0.4) lib/journey/router.rb:56:in `call'
actionpack (3.2.8) lib/action_dispatch/routing/route_set.rb:600:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
rack (1.4.1) lib/rack/etag.rb:23:in `call'
rack (1.4.1) lib/rack/conditionalget.rb:25:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/head.rb:14:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/flash.rb:242:in `call'
rack (1.4.1) lib/rack/session/abstract/id.rb:205:in `context'
rack (1.4.1) lib/rack/session/abstract/id.rb:200:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/cookies.rb:339:in `call'
activerecord (3.2.8) lib/active_record/query_cache.rb:64:in `call'
activerecord (3.2.8) lib/active_record/connection_adapters/abstract/connection_pool.rb:473:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (3.2.8) lib/active_support/callbacks.rb:405:in `_run__2589517259026276185__call__1369641113040304056__callbacks'
activesupport (3.2.8) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.8) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
activesupport (3.2.8) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.8) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/reloader.rb:65:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
bugsnag (1.2.5) lib/bugsnag/rack.rb:35:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
railties (3.2.8) lib/rails/rack/logger.rb:26:in `call_app'
railties (3.2.8) lib/rails/rack/logger.rb:16:in `call'
quiet_assets (1.0.1) lib/quiet_assets.rb:20:in `call_with_quiet_assets'
actionpack (3.2.8) lib/action_dispatch/middleware/request_id.rb:22:in `call'
rack (1.4.1) lib/rack/methodoverride.rb:21:in `call'
rack (1.4.1) lib/rack/runtime.rb:17:in `call'
activesupport (3.2.8) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.4.1) lib/rack/lock.rb:15:in `call'
actionpack (3.2.8) lib/action_dispatch/middleware/static.rb:62:in `call'
railties (3.2.8) lib/rails/engine.rb:479:in `call'
railties (3.2.8) lib/rails/application.rb:223:in `call'
railties (3.2.8) lib/rails/railtie/configurable.rb:30:in `method_missing'
~/Library/Application Support/Pow/Versions/0.4.0/node_modules/nack/lib/nack/server.rb:147:in `handle'
~/Library/Application Support/Pow/Versions/0.4.0/node_modules/nack/lib/nack/server.rb:99:in `rescue in block (2 levels) in start'
~/Library/Application Support/Pow/Versions/0.4.0/node_modules/nack/lib/nack/server.rb:96:in `block (2 levels) in start'
~/Library/Application Support/Pow/Versions/0.4.0/node_modules/nack/lib/nack/server.rb:86:in `each'
~/Library/Application Support/Pow/Versions/0.4.0/node_modules/nack/lib/nack/server.rb:86:in `block in start'
~/Library/Application Support/Pow/Versions/0.4.0/node_modules/nack/lib/nack/server.rb:66:in `loop'
~/Library/Application Support/Pow/Versions/0.4.0/node_modules/nack/lib/nack/server.rb:66:in `start'
~/Library/Application Support/Pow/Versions/0.4.0/node_modules/nack/lib/nack/server.rb:13:in `run'
~/Library/Application Support/Pow/Versions/0.4.0/node_modules/nack/bin/nack_worker:4:in `<main>'
When you use YAML.dump to serialize an object in Ruby, the class name is use as part of the Yaml tag so that the correct class can be used when loading the object. For example:
require 'yaml'
class Foo; end
puts YAML.dump Foo.new
produces
--- !ruby/object:Foo {}
When you use YAML.load on that string, Psych knows what class to instantiate for the deserialized object.
If you try to call YAML.load on a Yaml string that specifies a class that hasn’t been defined, then you will get the error:
require 'yaml'
# No Bar class has been defined
YAML.load '--- !ruby/object:Bar {}'
produces:
/Users/matt/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:312:in `path2class': undefined class/module Bar (ArgumentError)
from /Users/matt/.rvm/rubies/ruby-1.9.3-p327/lib/ruby/1.9.1/psych/visitors/to_ruby.rb:312:in `resolve_class'
...
This is because Psych needs to create an instance of class Bar, but doesn’t have the definition of the class available. This explains why adding require 'whatever' before loading the Yaml works – now Ruby has the definition of the class loaded and so can create an instance of it (note that there is no definitive link between class name and file name in Ruby, it’s just convention).
The solution therefore is to make sure that when you’re loading any Ruby objects from Yaml you have already required any files that may contain definitions of any classes potentially in that Yaml.
Matt's Answer provides necessary details.
But when I do changes in code and then do some task, that de-serializes some data, without page load (in AJAX) then it fails with same error.
It's better to use require_dependency than require to autoload your changes.
In case of module (not tested with class) and de-serializing using YAML, you can also instantiate your Module before de-serializing with require to fix the issue. See here.
Source: SO answer and Psych issue report in Github
P.S: This problem persists only in Development as config.cache_classes is enable in Production.
Amending to Matt's answer. In lieu of a pure-hash based solution (which the Psych team seems to have no interest in doing), modify the header string to strip off the object classification. I did this simply with the following code.
yamltext = File.read("somefile","r")
yamltext.sub!(/^--- \!.*$/,'---')
hash = YAML.load(yamltext)
This might fail (I don't know) if the input stream consists of several documents with different object classifiers (I dont know if that's even valid).